A. Field of the Invention
The present invention relates to a system for assessing movement and agility skills and, in particular to a wireless position tracker for continuously tracking and determining player position during movement in a defined physical space through player interaction with tasks displayed in a computer generated, specially translated virtual space for the quantification of the player's movement and agility skills based on time and distance traveled in the defined physical space.
B. The Related Art
Various means, both in terms of protocol and instrumentation, have been proposed for assessing and enhancing sport-specific movement capabilities. None, however, fulfill the requirements for validity, objectivity and accuracy as does the novel measurement constructs of the present invention.
Specific to the present invention, none create an accurate analog of the complex play between offensive and defensive opponents engaged in actual competition with seamless dynamic cueing, continuous position tracking in all relevant planes of movement and sport relevant movement challenges.
The present invention, for the purposes of evaluating a player's sport-specific movement capabilities, tracks the player's positional changes in three degrees (three dimensions) of freedom in real time. Computer-generated dynamic cues replicate the challenges of actual sports competition, as the purpose of the present invention is to measure the player's ability to perform unplanned or planned lateral movements, maximal accelerations and decelerations, abrupt positional changes and the like in a valid testing and training sports simulation.
Specifically, no prior art was uncovered that teaches the core elements of a novel measurement construct of movement capabilities that can be characterized as a "synchronous relationship".
In the context of interactive sports simulations, a synchronous relationship is defined as the player's ability to minimize spatial differences (deviations) over a time interval between his or her vector movements in the physical world coincidental to the vector movements of the dynamic cues that can be expressed as a "virtual opponent".
Certain protocols of the present invention reward the player for successfully minimizing the aforementioned spatial differences over a time interval, thereby enabling the player to move synchronously with the dynamic cueing that may be expressed as a virtual opponent. Uniquely assessed is the player's ability to maintain a synchronous relationship with the virtual opponent.
Alternatively, the dynamic cueing can present movement challenges that assess the player's ability to create an asynchronous event. In the contest of interactive sports simulations, asynchronicity is defined as the player's ability to maximize spatial differences over a time interval between his or her vector movements in the physical world relative to the vector movements of the dynamic cues that can be expressed as a "virtual opponent".
Asynchronicity creates an "out of phase" state relative to the movement of the virtual opponent. In a sports context, an asynchronous event ot sufficient duration allows the player to "evade" or "escape" the virtual opponent.
To quantify the player's ability to either create an asynchronous event, or maintain a synchronous relationship, nine novel measurement constructs have been created. Each of these constructs measure one aspect of the player's global movement skills. Together, these constructs provide valuable information about the player's overall movement capabilities: (Each are disclosed in greater detail elsewhere in this document.)
Compliance (the ability of the player to maintain synchronous movement.) PA1 Opportunity (the ability of the player to create an asynchronous movement event) PA1 Dynamic Reaction Time (the elapsed time for the player to react to attempts of the virtual opponent to create an asynchronous event) PA1 Phase Lag (the elapsed time player is "out-of-synch") PA1 First Step Quickness (the player's velocity, acceleration, and/or power while attempting to maintain a synchronous relationship or to create an asynchronous movement event) PA1 Reactive Bounding (the player's vertical displacements while attempting to maintain a synchronous relationship with the virtual opponent or to create an asynchronous movement event) PA1 Sports Posture (the player's stance or vertical body position that maximized sport specific performance) PA1 Functional Cardio-respiratory Status (assessment and training of the player's cardiac response during performance of sport specific movement) PA1 Vector Changes & Reactive Cutting (the ability of the player to execute abrupt positional changes in response to a virtual opponent) PA1 1.) Skills involving control of the body independent from other players; and PA1 2.) Skills including reactions to other players in the sports activity. PA1 Proprietary optical sensing electronics (discussed below) for determining, in essentially real time, the player's three dimensional positional changes in three or more degrees of freedom (three dimensions). PA1 Computer controlled sport specific cueing that evokes or prompts sport specific responses from the player. In certain protocols of the present invention, the sport specific cueing could be characterized as a "virtual opponent", that is preferably--but not necessarily--kinematically and anthropomorphically correct in form and action. Though the virtual opponent could assume many forms, the virtual opponent is responsive to, and interactive with, the player in real time without any perceived visual lag. The virtual opponent continually delivers and/or responds to stimuli to create realistic movement challenges for the player. The movement challenges are typically comprised ot relatively short, discrete movement legs, sometimes amounting to only a few inches of displacement of the player's center of mass. Such movement legs are without fixed start and end positions, necessitating continual tracking of the player's position for meaningful assessment.
Five patents are believed to be relevant as representative of the state-of-the art:
Erickson, U.S. Pat. No. 5,524,637 teaches means for measuring physical exertion, expressed as calories, as the game player or exerciser runs or walks in place. In one embodiment a video camera senses vertical (Y plane) oscillations of the player's body as the player watches a screen displaying a virtual landscape that "scrolls past" the player at a rate proportional to the vertical oscillations of the player either running or walking in place. Erickson also teaches continuous monitoring of heart rate during these two unconstrained activities. Erickson does not deliver dynamic cueing for the purposes of quantifying movement capabilities. Erickson does not provide for X or Z plane movement challenges requisite tor the present invention's performance measurements. Nor does Erickson teach means for cycling the heart rate to mimic the demands of sports competition. Essentially, Erickson's invention is an entertaining substitution for a conventional treadmill.
French et. al. U.S. Pat. No. 5,469,740 discloses a testing field that incorporates a multiplicity of force platforms coupled to a display screen. The position of the player is known only when the player is positioned on the force platforms. French does not provide means of continuously tracking the player during movement, nor of determining the direction of player's movement in between force platforms. The force platforms are placed at known fixed distances to enable accurate measurement of velocities, but without continuous tracking in three degrees of freedom, accelerations can not be determined.
French et al provides valid measures of agility, but does not continually track the player's positional changes, which are requisite to evaluating the present invention's Phase constructs.
Silva et al., U.S. Pat. No. 4,751,642 creates a computer simulation of the psychological conditions such as crowd noise associated with sports competition. Silva has no sensing means for tracking the player's movement continuously, but relies only on switches mounted to implements such as a ball to indicate when a task was completed. The continuous position of the athlete is unknown, therefore Silva's invention could not test or train any of the current invention's measurement constructs.
Blair et al., U.S. Pat. No. 5,239,463 employs wireless position tracking to track an observer's position to create a more realistic interaction between the game animation and the observer or player. Blair does not teach quantification of any of the present invention's measurement constructs, nor does he create a sports simulation as contemplated by this present invention.
Kosugi et al., U.S. Pat. No. 5,229,756 teaches means for creating an interactive virtual boxing game where the game player's movement controls the movement of a virtual image that "competes" with a virtual boxer (virtual "opponent"). The virtual image is said to respond accurately to the movement of a human operator.
Kosugi does not continuously track the player's position, only the location of one of the player's feet is known at such times as the player places a foot onto one of eight force platforms. Though the location of one foot can be assumed, the actual position of the body can only be inferred. Without means for continuous, real time tracking of the body, huge gaps in time exist between successive foot placements, dampening the quality of the simulation and precluding performance measures of acceleration, velocity and the like.
Unlike French, et al., the player's starting point, which is the center of the force sensing mat, is not sensored. Consequently, measurements of reaction time, velocity and the like could not be quantified.
Since the real time position of the player's center of gravity (the body center) is unknown, Kosugi's device is unable to perform any of the measurement constructs associated with Phase.
Additionally, Kosugi does not provide for sufficient movement area (movement options) to actually evaluate sport relevant movement capabilities. Kosugi has only eight force platforms, each requiring only a half step of the player to impact.
Kosugi does not teach quantification of any of the present invention's measurement constructs; for that matter, he does not teach quantification of any performance constructs. His game awards the player with points for "successful" responses.
Sports specific skills can be classified into two general conditions:
The former includes posture and balance control, agility, power and coordination. These skills are most obvious in sports such as volleyball, baseball, gymnastics, and track and field that demand high performance from an individual participant who is free to move without opposition from a defensive player. The latter encompasses interaction with another player-participant. This includes various offense-defense situations, such as those that occur in football, basketball, soccer, etc.
Valid testing and training of sport-specific skills requires that the player be challenged by unplanned cues which prompt player movement over distances and directions representative of actual game play. The player's optimum movement path should be selected based on visual assessment of his or her spatial relationship with opposing players and/or game objective. A realistic simulation must include a sports relevant environment. Test methods prompting the player to move to fixed ground locations are considered artificial. Nor are test methods employing static or singular movement cues such as a light or a sound consistent with accurate simulations of actual competition in many sports.
To date, no accurate, real time model of the complex, constantly changing, interactive relationship between offensive and defensive opponents engaging in actual competition exists. Accurate and valid quantification of sport-specific movement capabilities necessitates a simulation having fidelity with real world events.
At the most primary level, sports such as basketball, football and soccer can be characterized by the moment to moment interaction between competitors in their respective offensive and defensive roles. It is the mission of the player assuming the defensive role to "contain", "guard", or neutralize the offensive opponent by establishing and maintaining a real-time synchronous relationship with the opponent. For example, in basketball, the defensive player attempts to continually impede the offensive player's attempts to drive to the basket by blocking with his or her body the offensive player's chosen path, while in soccer the player controlling the ball must maneuver the ball around opposing players.
The offensive player's mission is to create a brief asynchronous event, perhaps of only a few hundred milliseconds in duration, so that the defensive player's movement is no longer in "phase" with the offensive player's. During this asynchronous event, the defensive player's movement no longer mirrors, i.e. is no longer synchronous with, his or her offensive opponent. At that moment, the defensive player is literally "out of position" and therefore is in a precarious position, thereby enhancing the offensive player's chances of scoring. The offensive player can create an asynchronous event in a number of ways. The offensive player can "fake out" or deceive his or her opponent by delivering purposefully misleading information as to his or her immediate intentions. Or the offensive player can "overwhelm" his opponent by abruptly accelerating the pace of the action to levels exceeding the defensive player's movement capabilities.
To remain in close proximity to an offensive opponent, the defensive player must continually anticipate or "read" the offensive player's intentions. An adept defensive player will anticipate the offensive player's strategy or reduce the offensive player's options to those that can easily be contained. This must occur despite the offensive player's attempts to disguise his or her actual intentions with purposely deceptive and unpredictable behavior. In addition to being able to "read", i.e., quickly perceive and interpret the intentions of the offensive player, the defensive player must also possess adequate sport-specific movement skills to establish and maintain the desired (from the perspective of the defensive player) synchronous spatial relationship.
These player-to-player interactions are characterized by a continual barrage of useful and purposefully misleading visual cues offered by the offensive player and constant reaction and maneuvering by the defensive participant. Not only does the defensive player need to successfully interpret visual cues "offered" by the offensive player, but the offensive player must also adeptly interpret visual cues as they relate to the defensive player's commitment, balance and strategy. Each player draws from a repertoire ot movement skills which includes balance and postural control, the ability to anticipate defensive responses, the ability to generate powerful, rapid, coordinated movements, and reaction times that exceed that of the opponent. These sport-specific movement skills are often described as the functional or motor related components of physical fitness.
The interaction between competitors frequently appears almost chaotic, and certainly staccato, as a result of the "dueling" for advantage. The continual abrupt, unplanned changes in direction necessitate that the defensive player maintain control over his or her center of gravity throughout all phases of movement to avoid over committing. Consequently, movements of only fractions of a single step are common for both the defensive and offensive players. Such abbreviated movements insure that peak or high average velocities are seldom, if ever, are achieved. Accordingly, peak acceleration and power are more sensitive measures of performance in the aforementioned scenario. Peak acceleration of the center of mass can be achieved more rapidly than peak velocity, often in one step or less, while power can relate the acceleration over a time interval, making comparisons between players more meaningful.
At a secondary level, all sports situations include decision-making skills and the ability to focus on the task at hand. The present invention simulation trains participants in these critical skills. Therefore, athletes learn to be "smarter" players due to increased attentional skills, intuition, and critical, sports related reasoning.
Only through actual game play, or truly accurate simulation of game play, can the ability to correctly interpret and respond to sport specific visual cues be honed. The same requirement applies to the refinement of the sport-specific components of physical fitness that is essential for adept defensive and offensive play. These sport-specific components include reaction time, balance, stability, agility and first step quickness.
Through task-specific practice, athletes learn to successfully respond to situational uncertainties. Such uncertainties can be as fundamental as the timing of the starter's pistol, or as complex as detecting and interpreting continually changing, "analog" stimuli presented by an opponent. To be task-specific, the type of cues delivered to the player must simulate those experienced in the player's sport. Task-specific cueing can be characterized, for the purposes of this document, as either dynamic or static.
Dynamic cueing delivers continual, "analog" feedback to the player by being responsive to, and interactive with, the player. Dynamic cueing is relevant to sports where the player must possess the ability to "read" and interpret "telegraphing" kinematic detail in his or her opponent's activities. Players must also respond to environmental cues such as predicting the path of a ball or projectile for the purposes of intercepting or avoiding it. In contrast, static cueing is typically a single discreet event, and is sport relevant in sports such a track and field or swimming events. Static cues require little cerebral processing and do not contribute to an accurate model of sports where there is continuous flow of stimuli necessitating sequential, real time responses by the player. At this level, the relevant functional skill is reaction time, which can be readily enhanced by the present invention's simulation.
In sports science and coaching, numerous tests of movement capabilities and reaction time are employed. However, these do not subject the player to the type and frequency of sport-specific dynamic cues requisite to creating an accurate analog of actual sports competition described above.
For example, measures of straight-ahead speed such as the 100-meter and 40 yard dash only subject the player to one static cue, i.e., the sound of the gun at the starting line. Although the test does measure a combination of reaction time and speed, it is applicable to only one specific situation (running on a track) and, as such, is more of a measurement of capacity, not skill. In contrast, the player in many other sports, whether in a defensive or offensive role, is continually bombarded with cues that provide both useful and purposely misleading information as to the opponent's immediate intentions. These dynamic cues necessitate constant, real time changes in the player's movement path and velocity, such continual real-time adjustments preclude a player from reaching maximum high speeds as in a 100-meter dash. Responding successfully to dynamic cues places constant demand on a player's agility and the ability to assess or read the opposing player intentions.
There is another critical factor in creating an accurate analog of sports competition. Frequently, a decisive or pivotal event such as the creation of an asynchronous event does not occur from a preceding static or stationary position by the players. For example, a decisive event most frequently occurs while the offensive player is already moving and creates a phase shift by accelerating the pace or an abrupt change in direction. Consequently, it is believed that the most sensitive indicators of athletic prowess occur during abrupt changes in vector direction or pace of movement from "pre-existing movement". All known test methods are believed to be incapable of making meaningful measurements during these periods.